Keeping a vehicle stationary while it is on an inclined surface can present particular challenges for electric vehicles. For example, if an electric machine, such as an electric motor, is used exclusively to maintain the vehicle position—i.e., the friction brakes are not employed—the electric motor may overheat if it is maintained in one position for too long. This may be the result of a high concentration of current within one or two phases of the inverter and stator, which, in addition to merely raising the temperature of the motor, can result in a non-uniform temperature increase, creating the potential for localized component damage.
Some control systems for electric vehicles may employ a mitigation strategy that shuts down the motor upon the occurrence of an undesirable event, such as a critical temperature being reached. This can result in vehicle behavior that may not be expected by the vehicle operator, and therefore is undesirable. Therefore, a need exists for a vehicle and method for controlling a vehicle to implement a thermal mitigation strategy that allows the vehicle to be maintained in a stationary position for a longer period of time before the motor must be completely shut down.